You can find wide ranges in pricing for both Judo and Karate gis, based on quality of construction, materials, and brand-name.

If you check the various on-line auction sites, you can find a new Judo gi for $30 or even less.

But, following Janet's post, Judo gi are designed for a grappling art...they are grabbed, yanked, tugged, pulled, etc. Karate gi tend to be lighter in weight and not as sturdily constructed to allow for movements of a punching/kicking art.